[PATCH v3 0/4] xen/pv: sanitize xen pv guest msr accesses

From: Juergen Gross
Date: Wed Oct 05 2022 - 07:03:14 EST

Historically when running as Xen PV guest all MSR accesses have been
silently swallowing any GP faults, even when the kernel was using not
the *msr_safe() access functions.

Change that by making the behavior controllable via kernel config and
via a boot parameter.

This will help finding paths where MSRs are being accessed under Xen
which are not emulated by the hypervisor.

Changes in V3:
- new patch 2
- addressed comments

Juergen Gross (4):
xen/pv: add fault recovery control to pmu msr accesses
xen/pv: fix vendor checks for pmu emulation
xen/pv: refactor msr access functions to support safe and unsafe
xen/pv: support selecting safe/unsafe msr accesses

.../admin-guide/kernel-parameters.txt | 6 ++
arch/x86/xen/Kconfig | 9 ++
arch/x86/xen/enlighten_pv.c | 99 +++++++++++++------
arch/x86/xen/pmu.c | 71 +++++++------
4 files changed, 127 insertions(+), 58 deletions(-)